Persistent polyclonal B lymphocytosis with binucleated lymphocytes: a study of 25 cases. Groupe Français d'Hématologie Cellulaire.

Persistent and polyclonal lymphocytosis of B lymphocytes (PPBL) with binucleated lymphocytes is an entity characterized by a polyclonal lymphocytosis. The lymphocytosis is stable for years and binucleated lymphocytes are detected on peripheral blood smears. We previously described +i(3q) as a recurrent chromosomal abnormality in seven PPBL patients. In this study we report a large series of 25 PPBL patients and demonstrated that PPBL was associated with +i(3q) in 77% of cases, premature chromosome condensation (PCC) in 50% and both abnormalities in 41% of cases. Furthermore, we demonstrated that i(3q) was present in a minority of B cells, restricted to B lymphocytes independently of the kappa or lambda light Ig chain expression, and exclusively observed in non-binucleated cells. The benign clinical course of PPBL and the lack of biological evolution in the majority of cases suggest that recognition of these disorders is so important that aggressive therapy in PPBL has to be avoided. Whether this syndrome represents a premalignant or benign disease remains unclear. The persistence of cytogenetic abnormalities after stopping tobacco use suggests no association with cigarette smoking.